U.S. patent number 11,293,493 [Application Number 16/473,472] was granted by the patent office on 2022-04-05 for flexible bearing retainer for multistage centrifugal pump.
This patent grant is currently assigned to Grundfos Holding A/S. The grantee listed for this patent is Grundfos Holding A/S. Invention is credited to Brian Lundsted Poulsen.
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United States Patent |
11,293,493 |
Lundsted Poulsen |
April 5, 2022 |
Flexible bearing retainer for multistage centrifugal pump
Abstract
The present invention relates to a centrifugal pump and a
bearing retainer for the centrifugal pump. The centrifugal pump has
a shaft, a bearing for supporting the shaft, and a bearing retainer
for the bearing. The bearing retainer comprises a ring section
adapted to surround the bearing and an elastic section adjacent the
ring section, wherein the elastic section comprises multiple slits,
dividing the elastic section into multiple resilient parts, wherein
the multiple resilient parts are adapted to receiving and
supporting the bearing, thereby creating a compression force in
radial direction perpendicular to the axis of the shaft, allowing
the bearing retainer to hold the bearing in a fixed position with
respect to the bearing retainer.
Inventors: |
Lundsted Poulsen; Brian
(Langaa, DK) |
Applicant: |
Name |
City |
State |
Country |
Type |
Grundfos Holding A/S |
Bjerringbro |
N/A |
DK |
|
|
Assignee: |
Grundfos Holding A/S
(Bjerringbro, DK)
|
Family
ID: |
57777448 |
Appl.
No.: |
16/473,472 |
Filed: |
December 26, 2017 |
PCT
Filed: |
December 26, 2017 |
PCT No.: |
PCT/DK2017/050452 |
371(c)(1),(2),(4) Date: |
June 25, 2019 |
PCT
Pub. No.: |
WO2018/121827 |
PCT
Pub. Date: |
July 05, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20190368548 A1 |
Dec 5, 2019 |
|
Foreign Application Priority Data
|
|
|
|
|
Dec 28, 2016 [EP] |
|
|
16207125 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16C
17/22 (20130101); F16C 35/077 (20130101); F16C
37/00 (20130101); F04D 29/046 (20130101); F16C
33/04 (20130101); F04D 29/669 (20130101); F16C
27/02 (20130101); F16C 35/02 (20130101); F16C
37/002 (20130101); F16C 2360/44 (20130101); Y10S
384/905 (20130101) |
Current International
Class: |
F04D
29/046 (20060101); F16C 17/22 (20060101); F16C
33/04 (20060101); F16C 27/02 (20060101); F16C
37/00 (20060101); F16C 35/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
903762 |
|
Feb 1954 |
|
DE |
|
2169469 |
|
Sep 1973 |
|
FR |
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2532700 |
|
Mar 1984 |
|
FR |
|
Other References
Extended European Search Report; European Patent Office; European
Application No. 16207125.2; dated Mar. 28, 2017; 8 pages. cited by
applicant .
International Search Report; European Patent Office; International
Application No. PCT/DK2017/050452; dated Mar. 7, 2018; 4 pages.
cited by applicant .
Written Opinion of the International Searching Authority; European
Patent Office; International Application No. PCT/PCT/DK2017/050452;
dated Mar. 7, 2018; 5 pages. cited by applicant .
International Preliminary Report on Patentability; The
International Bureau of WIPO; International Application No.
PCT/DK2017/050452; dated Jul. 2, 2019; 6 pages. cited by applicant
.
Communication pursuant to Article 94(3) EPC; European Patent
Office; European Application No. 17828838.7; dated Jun. 10, 2021; 5
pages. cited by applicant.
|
Primary Examiner: Lebentritt; Michael
Assistant Examiner: Delrue; Brian Christopher
Attorney, Agent or Firm: Taft Stettinius & Hollister
LLP
Claims
The invention claimed is:
1. A bearing retainer configured for assembly with a bearing to
support a shaft of a pump, said bearing retainer comprising: at
least one ring section adapted to surround the bearing, said ring
section having an inner radius perpendicular to an axis of the
shaft, said ring section having a variable thickness in the
circumferential direction; at least one elastic section adjacent
said ring section, wherein at least a part of said elastic section
has an inner radius perpendicular to the axis of the shaft, which
inner radius is smaller than said radius of said ring section, said
elastic section comprising multiple slits, dividing said elastic
section into multiple resilient parts; said multiple resilient
parts being adapted to allowing receiving and supporting the
bearing, thereby creating a compression force in radial direction
perpendicular to the axis of the shaft, allowing said bearing
retainer to hold the bearing in a fixed position with respect to
said bearing retainer; wherein said elastic section comprises an
oblique subsection adjacent said ring section, and a cylindrical
subsection adjacent said oblique subsection, wherein said oblique
subsection comprises a wall which is slanted with respect to the
shaft of the pump, and said cylindrical subsection comprises a wall
which is parallel to the shaft of the pump.
2. The bearing retainer according to claim 1, wherein said multiple
resilient parts allows receiving and supporting the bearing at a
first temperature, thereby creating a compression force in radial
direction perpendicular to the shaft, and wherein said multiple
resilient parts allows maintaining a compression force in radial
direction perpendicular to the shaft at a temperature higher than
said first temperature.
3. The bearing retainer according to claim 1, wherein said multiple
resilient parts are adapted to allow said bearing retainer to
remain in contact with the bearing when the temperature
changes.
4. The bearing retainer of claim 1, further comprising: an
additional ring section adjacent said elastic section, such that
said elastic section is positioned between said ring section and
said additional ring section.
5. The bearing retainer of claim 1, further comprising: an
additional elastic section adjacent said ring section, such that
said ring section is positioned between said elastic section and
said additional elastic section.
6. The bearing retainer according to claim 1, wherein said bearing
retainer has a first end and a second end opposite said first end
in an axial direction, and further has a center positioned in the
middle between said first end and said second end, and wherein said
bearing retainer has a smaller external diameter at said center of
said bearing retainer than the external diameter at said ends of
said bearing retainer.
7. The bearing retainer according to claim 1, wherein said multiple
slits have a length to wide ratio of at least 2:1, more preferred
at least 3:1, preferably at least 4:1, more preferred at least 5:1,
preferably at least 6:1, more preferred at least 7:1, preferably at
least 8:1, more preferred at least 9:1, preferably at least 10:1,
more preferred at least 11:1, preferably at least 12:1, more
preferred at least 15:1.
8. The bearing retainer according to claim 1 wherein said multiple
slits extend into said oblique subsection of said elastic
section.
9. A bearing retainer configured for assembly with a bearing to
support a shaft of a pump, said bearing retainer comprising: at
least one ring section adapted to surround the bearing, said ring
section having an outer profile that is wave formed, said ring
section having an inner radius perpendicular to the axis of the
shaft wherein said inner radius is constant; at least one elastic
section adjacent said ring section, wherein at least a part of said
elastic section has an inner radius perpendicular to an axis of the
shaft, which inner radius is smaller than said radius of said ring
section; said elastic section comprising multiple slits, dividing
said elastic section into multiple resilient parts; said multiple
resilient parts being adapted to allowing receiving and supporting
the bearing, thereby creating a compression force in radial
direction perpendicular to the axis of the shaft, allowing said
bearing retainer to hold the bearing in a fixed position with
respect to said bearing retainer; and wherein said elastic section
comprises an oblique subsection adjacent said ring section, and a
cylindrical subsection adjacent said oblique subsection, wherein
said oblique subsection comprises a wall which is slanted with
respect to the shaft of the pump, and said cylindrical subsection
comprises a wall which is parallel to the shaft of the pump.
10. The bearing retainer according to claim 9, wherein said
multiple resilient parts allows receiving and supporting the
bearing at a first temperature, thereby creating a compression
force in radial direction perpendicular to the shaft, and wherein
said multiple resilient parts allows maintaining a compression
force in radial direction perpendicular to the shaft at a
temperature higher than said first temperature.
11. The bearing retainer according to claim 9, wherein said
multiple resilient parts are adapted to allow said bearing retainer
to remain in contact with the bearing when the temperature
changes.
12. The bearing retainer according to claim 9, wherein said bearing
retainer has a first end and a second end opposite said first end
in an axial direction, and further has a center positioned in the
middle between said first end and said second end, and wherein said
bearing retainer has a smaller external diameter at said center of
said bearing retainer than the external diameter at said ends of
said bearing retainer.
13. The bearing retainer according to claim 9, wherein said
multiple slits have a length to wide ratio of at least 5:1.
14. The bearing retainer according to claim 9, wherein said
multiple slits extend into said oblique subsection of said elastic
section.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. National Phase of International PCT
Application No. PCT/DK2017/050452 filed on Dec. 26, 2017, which
claims priority to European Patent Application No. 16207125.2 filed
Dec. 28, 2016, each of which are incorporated herein by reference
in their entirety.
The present invention relates to a centrifugal fluid pump and a
bearing retainer for a centrifugal fluid pump. In particular, it
relates to a multistage centrifugal pump and a bearing retainer for
a multistage centrifugal pump.
TECHNICAL BACKGROUND
Multi-stage centrifugal pump units are described in the patent
applications US 2012/0251308 A1 and US 2016/0108922 A1.
The U.S. Pat. No. 2,956,841 concerns a bearing and a mounting for
the bearing, in particular a sleeve-type bearing which is thermally
expansible. The bearing is allegedly particularly for use with a
liquid metal motor-pump combination. The patent relates to a
bearing assembly using a plurality of circumferentially spaced leaf
springs. The patent inter alia aims at providing means for
permitting relative thermal expansion.
The JP patent application H08-170646 (Leading to JP2711434)
concerns the problem of preventing a slide bearing and a rotation
shaft from corotating in a high temperature environment. The
problem is allegedly solved by interposing a spacer between a slide
bearing formed of ceramics and a holding member formed of metal
with a coefficient of thermal expansion larger than the bearing.
The spacer is cylindrical and formed of metal with a coefficient of
thermal expansion larger than the holding member. Thermal expansion
of the thickness of the spacer compensates the difference between
the thermal expansion of the slide bearing and the holding member.
The spacer may comprise slits, allowing absorbing the expansion of
the spacer along the circumferential direction of the spacer.
The U.S. Pat. No. 7,056,027 B2 concerns a bearing for rotatably
supporting a cylindrical shaft within a frame cylindrical support
surface in which the shaft is subject to thermal expansion, the
bearing being deformable within elastic limits permitting the
internal diameter of the bearing surface to expand to accept
thermal expansion of the shaft.
The U.S. Pat. No. 2,506,404 B2 concerns a bearing assembly for
rotating apparatus, which bearing assembly comprises a housing
member, a bearing positioned in said housing member and spaced from
an end wall thereof, a resilient cap member positioned in the
opening between said end wall and said bearing and having resilient
spring fingers engaging a circumferential surface of said surface
of said housing and the outer surface of said bearing for applying
radial pressure thereto.
The U.S. Pat. No. 4,981,390 B2 concerns a tolerance ring with
radial projections to achieve unidirectional or bidirectional axial
retention, or angular retention relative to at least one abutting
cylindrical surface.
The manufacturing of bearings, and retainers or holders for
bearings, usually requires very strict production tolerances. There
is a need to relax the production tolerances to reduce costs of
manufacturing.
SUMMARY OF THE INVENTION
Against this background, a bearing retainer has been developed. The
bearing retainer of the invention comprises sections, which are
flexible in a radial direction, allowing receiving and holding a
bearing.
This provides for a bearing retainer wherein the production
tolerances are larger than for a traditional, rigid bearing
retainer. Further, a bearing retainer of the invention may be used
at elevated temperatures and retain contact with a bearing in spite
of different thermal expansion coefficients of bearing retainer and
bearing.
According to an aspect, the present invention concerns a
centrifugal pump having a shaft and a bearing for supporting said
shaft, said centrifugal pump further comprising a bearing retainer
for said bearing, wherein said bearing retainer comprises: at least
one ring section adapted to surround the bearing, said ring section
having an inner radius perpendicular to the axis of said shaft; at
least one elastic section adjacent said ring section, wherein at
least a part of said elastic section has an inner radius
perpendicular to the axis of said shaft, which inner radius is
smaller than said radius of said ring section; said elastic section
comprising multiple slits, dividing said elastic section into
multiple resilient parts; said multiple resilient parts being
adapted to allowing receiving and supporting the bearing, thereby
creating a compression force in radial direction perpendicular to
the axis of said shaft, allowing said bearing retainer to hold the
bearing in a fixed position with respect to said bearing
retainer.
According to an aspect, the present invention concerns a
centrifugal pump having a shaft and a bearing for supporting said
shaft, said centrifugal pump further comprising a bearing retainer
for said bearing, wherein said bearing retainer comprises: at least
one ring section adapted to surround the bearing, said ring section
having an inner radius perpendicular to the axis of said shaft; at
least one elastic section adjacent said ring section, wherein at
least a part of said elastic section has an inner radius
perpendicular to the axis of said shaft, which inner radius is
smaller than said radius of said ring section; said elastic section
comprising multiple slits, dividing said elastic section into
multiple resilient parts; said multiple resilient parts being
adapted to allowing receiving and supporting the bearing, thereby
creating a compression force in radial direction perpendicular to
the axis of said shaft, allowing said bearing retainer to hold the
bearing in a fixed position with respect to said bearing retainer;
wherein said elastic section comprises an oblique subsection
adjacent said ring section, and a cylindrical subsection adjacent
said oblique subsection, wherein said oblique subsection comprises
a wall which is slanted with respect to the shaft of the pump, and
said cylindrical subsection comprises a wall which is parallel to
the shaft of the pump.
The centrifugal pump is preferably a centrifugal fluid pump. The
fluid is preferably a liquid.
According to another aspect, the present invention concerns a
bearing retainer for a bearing for supporting the shaft of a pump,
said bearing retainer comprising: at least one ring section adapted
to surround the bearing, said ring section having an inner radius
perpendicular to the axis of the shaft; at least one elastic
section adjacent said ring section, wherein at least a part of said
elastic section has an inner radius perpendicular to the axis of
the shaft, which inner radius is smaller than said radius of said
ring section; said elastic section comprising multiple slits,
dividing said elastic section into multiple resilient parts; said
multiple resilient parts being adapted to allowing receiving and
supporting the bearing, thereby creating a compression force in
radial direction perpendicular to the axis of the shaft, allowing
said bearing retainer to hold the bearing in a fixed position with
respect to said bearing retainer.
According to another aspect, the present invention concerns a
bearing retainer for a bearing for supporting the shaft of a pump,
said bearing retainer comprising: at least one ring section adapted
to surround the bearing, said ring section having an inner radius
perpendicular to the axis of the shaft; at least one elastic
section adjacent said ring section, wherein at least a part of said
elastic section has an inner radius perpendicular to the axis of
the shaft, which inner radius is smaller than said radius of said
ring section; said elastic section comprising multiple slits,
dividing said elastic section into multiple resilient parts; said
multiple resilient parts being adapted to allowing receiving and
supporting the bearing, thereby creating a compression force in
radial direction perpendicular to the axis of the shaft, allowing
said bearing retainer to hold the bearing in a fixed position with
respect to said bearing retainer; wherein said elastic section
comprises an oblique subsection adjacent said ring section, and a
cylindrical subsection adjacent said oblique subsection, wherein
said oblique subsection comprises a wall which is slanted with
respect to the shaft of the pump, and said cylindrical subsection
comprises a wall which is parallel to the shaft of the pump.
According to an aspect, the present invention concerns a bearing
connected to a bearing retainer according to the invention.
According to an aspect, the present invention concerns a
combination of a bearing retainer with a bearing, wherein said
combination is obtainable by inserting or pressing a bearing into a
bearing retainer according to the invention.
According to an aspect, the present invention concerns a
centrifugal pump comprising a bearing retainer according to the
invention, a bearing according to the invention, or a combination
of a bearing retainer with a bearing according the invention.
According to an aspect, the present invention concerns a use of a
bearing retainer according to the invention, a bearing according to
the invention, or a combination of a bearing retainer with a
bearing according to the invention, for supporting a bearing
stabilizing the shaft of a centrifugal pump.
The expression "axis of the shaft" refers to the axis of rotation
of the shaft.
The term "radius" is used about the distance from the axis of
rotation of the shaft of the pump to specific parts such as of the
bearing retainer, even that the specific parts and/or the bearing
retainer may not be circular.
The term "multiple" means more than one.
The term "slit" is here used about a long, narrow cut or opening in
a material, such as metal. A slit may provide improved resilience
or elasticity of the remaining material. A slit may be along a line
or it may have other shapes, such as being curved, C-shaped,
S-shaped or shaped like a wave.
A bearing retainer of the invention may be made by any conventional
method, and may also be manufactured by 3D printing. 3D printing
facilitates manufacturing of complicated shapes.
It is preferred that the bearing retainer is integrally formed, but
it may consist of more than one part.
It is preferred that the ring section and the elastic section are
positioned adjacent along an axis parallel to the shaft.
After insertion of the bearing into the bearing retainer, the
bearing will be held by the multiple resilient parts, acting as
leaf springs or arc shaped springs providing compression against
the side of the bearing. In this way, the bearing is held by
compression forces, after being inserted or pressed into the
bearing retainer. This provides a bearing retainer for which the
production tolerances are larger than for a traditional bearing
retainer. A traditional bearing retainer has dimensions which need
to be accurately adjusted to the dimensions of the bearing. The
resilient parts of the present invention allows a wider tolerance
in the manufacturing of the bearing retainer as well as the
bearing.
The term ring section does not necessarily imply circular, but may
be other shapes such as elliptical, corrugated or wave formed.
Preferably the bearing retainer is not cylindrical.
A bearing retainer of the invention is particularly useful for a
pump, which is a multistage centrifugal pump.
A bearing retainer of the invention may be fixed with respect to
the rest of a pump with any conventional means, such as by welding,
or it may e.g. be placed in a holder, which is fixed with respect
to the pump.
According to an embodiment, a bearing retainer of the invention is
welded to the inner guide cup of a guiding chamber of a centrifugal
pump.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
ring section comprises a closed or an open ring.
The ring section may optionally comprise a longitudinal aperture,
facilitating insertion into a holder of the bearing retainer. This
is in particular useful if the bearing retainer acts as a spacer
between a holding member and a bearing.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein the
bearing supports the shaft directly or indirectly.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
ring section is stiffer than said elastic section.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
elastic section comprises an oblique subsection adjacent said ring
section, and a cylindrical subsection adjacent said oblique
subsection, wherein said oblique subsection comprises a wall which
is slanted with respect to the shaft of the pump, and said
cylindrical subsection comprises a wall which is parallel to the
shaft of the pump.
In this embodiment, the slanted wall may be straight, linear and/or
curved. In the latter case, the slanted wall may form a curved
slope, connecting the ring section with the cylindrical
subsection.
The oblique subsection provides for an improved resilience of the
resilient parts. The bearing retainer may have an even wall
thickness, providing improved strength. The oblique subsection may
provide or allow for the production of a bearing retainer with even
wall thickness. The oblique subsection may provide a more resilient
mounting of the bearing. The oblique subsection may provide a high
radial interference, which will be particularly suitable for high
temperatures and/or large differences of temperatures.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein the
bearing retainer has an even wall thickness. An even wall thickness
may provide improved strength to the bearing retainer.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein the
at least one ring section (2) comprises a wall, and the at least
one elastic section (4) comprises a wall; and wherein the wall of
the at least one ring section (2) and the wall of the at least one
elastic section (4) has substantially the same and even wall
thickness.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein the
wall of said oblique subsection (17) and the wall of said
cylindrical subsection (18) has substantially the same and even
wall thickness.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein the
coefficient of thermal expansion for said bearing retainer is
larger than for the bearing.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple resilient parts allows receiving and supporting the
bearing at a first temperature, thereby creating a compression
force in radial direction perpendicular to the shaft, and wherein
said multiple resilient parts allows maintaining a compression
force in radial direction perpendicular to the shaft at a
temperature higher than said first temperature.
This provides a bearing retainer allowing operating a multistage
fuel pump at high temperatures, while maintaining contact between
the bearing retainer and the bearing.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple resilient parts are adapted to allow said bearing retainer
to remain in contact with the bearing when the temperature
changes.
Thereby co-rotation of the bearing with the shaft may be prevented.
A bearing retainer of the invention may be manufactured and
installed in a pump at room temperature, and still fulfill its role
to fixate the bearing at an elevated temperature.
The multiple resilient parts are adapted to allow said bearing
retainer to remain in contact with the bearing when the temperature
changes due to the choice of dimensions, shape and materials and
thus elasticity and resilience.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple resilient parts are adapted to allow said bearing retainer
to remain in contact with the bearing at a temperature of about
350.degree. C.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple resilient parts are adapted to allow said bearing retainer
to remain in contact with the bearing in the temperature interval
from room temperature up to at least 350.degree. C., preferably at
least 400.degree. C., more preferred at least 450.degree. C.,
preferably at least 500.degree. C., more preferred at least
550.degree. C., preferably at least 600.degree. C., more preferred
at least 650.degree. C., preferably at least 700.degree. C., more
preferred at least 750.degree. C., preferably at least 800.degree.
C., more preferred at least 850.degree. C.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple resilient parts are adapted to allow said bearing retainer
to remain in contact with the bearing at a temperature of at least
350.degree. C., preferably at least 400.degree. C., more preferred
at least 450.degree. C., preferably at least 500.degree. C., more
preferred at least 550.degree. C., preferably at least 600.degree.
C., more preferred at least 650.degree. C., preferably at least
700.degree. C., more preferred at least 750.degree. C., preferably
at least 800.degree. C., more preferred at least 850.degree. C.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, said bearing
retainer further comprising: an additional ring section adjacent
said elastic section, such that said elastic section is positioned
between said ring section and said additional ring section.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, said bearing
retainer further comprising: an additional elastic section adjacent
said ring section, such that said ring section is positioned
between said elastic section and said additional elastic
section.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer has a first end and a second end opposite said
first end in an axial direction, and further has a center
positioned in the middle between said first end and said second
end.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer has a first end and a second end opposite said
first end in an axial direction, and further has a center
positioned in the middle between said first end and said second
end, and wherein said bearing retainer has a smaller external
diameter at said center of said bearing retainer than the external
diameter at said ends of said bearing retainer.
The diameter is here measured in a direction perpendicular to the
shaft of the pump. While the term "diameter" is used, it does not
necessarily imply that the bearing retainer is circular or
cylindrical. The term "diameter" is used to refer to the distance
from one side of the bearing retainer, across the axis of rotation
of the shaft of the pump, to the opposite side of the bearing
retainer.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer has a first end and a second end opposite said
first end in an axial direction, and further has a center
positioned in the middle between said first end and said second
end, and wherein said bearing retainer has a larger external
diameter at said center of said bearing retainer than the external
diameter at said ends of said bearing retainer.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer has a first end and a second end opposite said
first end in an axial direction, and wherein said bearing retainer
has a smaller external diameter at one end of said bearing retainer
than the external diameter at the other end of said bearing
retainer.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer has a first end and a second end opposite said
first end in an axial direction, and wherein said bearing retainer
further comprises a sealing surface at one of said ends, said
sealing surface impeding fluid from passing between said bearing
retainer and the bearing.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer comprises a number of slits selected among 2, 3,
4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20
slits.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer has a first end and a second end opposite said
first end in an axial direction, wherein said multiple slits do not
extend to said ends of said bearing retainer.
In this embodiment the multiple slits protrude the wall of the
bearing retainer, such that said slits are surrounded by said
wall.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer has a first end and a second end opposite said
first end in an axial direction, wherein said multiple slits extend
to said ends of said bearing retainer.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple slits are elongated.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple slits have a length to wide ratio of at least 2:1, more
preferred at least 3:1, preferably at least 4:1, more preferred at
least 5:1, preferably at least 6:1, more preferred at least 7:1,
preferably at least 8:1, more preferred at least 9:1, preferably at
least 10:1, more preferred at least 11:1, preferably at least 12:1,
more preferred at least 15:1.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple slits extend into said ring section.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
multiple slits extend over at least 30%, preferably at least 40%,
more preferred at least 50%, preferably at least 60%, more
preferred at least 70%, preferably at least 80%, more preferred at
least 90% of the length of the bearing retainer as measured in a
direction along the axis of the shaft.
The multiple slits may be slanted with respect to the shaft of the
pump. The length of extension of said multiple slits may be
measured from one end of a slit to the other end of the slit in a
direction along the shaft of the pump.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer, wherein said elastic section
(4) comprises an oblique subsection adjacent said ring section (2),
wherein said oblique subsection comprises a wall which is slanted
with respect to the shaft of the pump, and wherein said multiple
slits (6) extend into said oblique subsection. This embodiment
provides improved resilience or elasticity of the multiple
resilient parts.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
bearing retainer comprises or consists of metal.
Preferably the bearing retainer comprises or consists of stainless
steel.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, said bearing
retainer being adapted to being inserted into a holder of said
bearing retainer.
In this embodiment the bearing retainer may act as a spacer between
the holder and the bearing.
According to an embodiment, the present invention concerns a
centrifugal pump or bearing retainer of the invention, wherein said
ring section of said bearing retainer comprises an aperture,
facilitating insertion into a holder of said bearing retainer.
According to an embodiment, the present invention concerns a
bearing connected to a bearing retainer according to the
invention.
According to an embodiment, the present invention concerns a
bearing of the invention, wherein said bearing comprises or
consists of ceramics.
According to an embodiment, the present invention concerns a
combination of a bearing retainer with a bearing, wherein said
combination is obtainable by inserting or pressing a bearing into a
bearing retainer according to the invention.
According to an embodiment, the present invention concerns a
centrifugal pump comprising a bearing retainer according to the
invention, a bearing according to the invention, or a combination
of a bearing retainer with a bearing according to the
invention.
According to an embodiment, the present invention concerns a use of
a bearing retainer according to the invention, a bearing according
to the invention, or a combination of a bearing retainer with a
bearing according to the invention, for supporting a bearing
stabilizing the shaft of a centrifugal pump.
FIGURES
Aspects and embodiments of the present invention are described
below, in a short description followed by a detailed description of
the Figures.
FIG. 1 shows a schematic longitudinal cross section of a
centrifugal pump according to an embodiment of the invention.
FIG. 2 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention.
FIG. 3 is a schematic representation of a bearing inside a bearing
retainer according to an embodiment of the invention.
FIG. 4 is a schematic representation of a bearing (left in the
picture) and a bearing retainer (right in the picture) according to
an embodiment of the invention.
FIG. 5 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention, wherein the
slits are oblique.
FIG. 6 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention, wherein the
elastic section comprises a part having a wave shaped form.
FIG. 7 shows a schematic top view of a cross section of a bearing
retainer according to an embodiment of the invention.
FIG. 8 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention, wherein the
slits are linear with a bend in each end.
FIG. 9 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention, wherein the
slits are shaped like a wave.
FIG. 10 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention, wherein the
slits are shaped like a wave.
FIG. 11 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention in a
holder.
FIG. 12 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention, wherein the
bearing retainer has multiple slits extending to the ring sections
of the bearing retainer.
FIG. 13 shows a schematic sectional view through the guiding
chamber of a centrifugal pump according to an embodiment of the
invention showing an unassembled bearing and a bearing retainer,
wherein the bearing may support the shaft of a pump. FIG. 13 is
rotated 180.degree. with respect to FIG. 1.
FIG. 14 is a schematic perspective representation of a bearing
retainer according to an embodiment of the invention holding a
bearing, wherein the bearing retainer has multiple slits extending
to the ring sections of the bearing retainer.
FIG. 15 shows a schematic side view of a cross section of a bearing
retainer according to an embodiment of the invention comprising two
elastic sections adjacent a ring section. A holder holds the
bearing retainer, which holds a bearing, supporting a shaft.
FIG. 16 shows a schematic side view of a cross section of a bearing
retainer according to an embodiment of the invention. The bearing
retainer holds a bearing and an additional bearing contacts and
co-rotates with the shaft of the pump.
FIG. 17 shows a schematic cross section of a bearing retainer
according to an embodiment of the invention. The front part of the
bearing retainer has been cut open revealing the inner backside of
the bearing retainer.
DETAILED DISCLOSURE
A more detailed description of the Figures follows below.
FIG. 1 shows a schematic longitudinal sectional view through a
centrifugal pump according to an embodiment of the invention. The
centrifugal pump comprises a bottom part having a pump foot (121)
on which the pump is supported, a flange (122) which surrounds a
suction branch consisting of an inlet (123) for suction and an
outlet (132) for creating pressure. The centrifugal pump has a
shaft (126) and a bearing (109) for supporting the shaft and a
bearing retainer (110) which supports the bearing. The axis of
rotation of the shaft, i.e. the axis of the shaft, is indicated
with a line (x-x). The centrifugal pump has a first pump stage
consisting of an impeller (124) and a stage guide (125) and the
centrifugal pump consists in total of three impellers and three
stage guides arranged vertically over one another. The centrifugal
pump further has a channel for liquid (130) and an outer stainless
steel tube (131). The centrifugal pump comprises a top part
consisting of a motorchair (127), a coupling-rotator (128) and a
shaft seal (129). The centrifugal pump further comprises a motor
(not shown) for rotating the shaft (126).
FIG. 2 is a schematic perspective representation of a bearing
retainer (10) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer
has a ring section (2) adapted to surround the bearing, wherein the
ring section has an inner radius perpendicular to the axis of the
shaft. The bearing retainer has one elastic section (4) adjacent
the ring section, wherein at least a part of the elastic section
has an inner radius perpendicular to the axis of the shaft, which
inner radius is smaller than the radius of the ring section. The
bearing retainer has a ring section (12) adjacent the elastic
section (4). The elastic section comprises multiple slits (6) which
are parallel to the axis of the shaft (not shown). The slits divide
the elastic section into multiple resilient parts (8). The multiple
resilient parts are adapted to receive and support the bearing and
creates a compression force in radial direction perpendicular to
the axis of the shaft. This allows the bearing retainer to hold the
bearing in a fixed position with respect to the bearing retainer.
The elastic section comprises an oblique subsection (17) adjacent
the ring section, which has a wall, which is slanted with respect
to the shaft of the pump. The bearing retainer further comprises a
cylindrical subsection (18) adjacent the oblique subsection, which
has a wall, which is parallel to the shaft of the pump.
FIG. 3 is a schematic representation of a bearing inside a bearing
retainer according to an embodiment of the invention. The bearing
is the non-rotating part of the full bearing. The other part, the
rotating part, is mounted on a shaft. Both bearing parts are made
of a ceramic material.
FIG. 4 is a schematic representation of a bearing (left in the
picture) and a bearing retainer (right in the picture) according to
an embodiment of the invention.
FIG. 5 is a schematic perspective representation of a bearing
retainer (510) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer
has a ring section (502) adapted to surround the bearing, wherein
the ring section has an inner radius perpendicular to the axis of
the shaft. The bearing retainer has one elastic section (504)
adjacent the ring section, wherein at least a part of the elastic
section has an inner radius perpendicular to the axis of the shaft,
which inner radius is smaller than the radius of the ring section.
The elastic section comprises multiple oblique slits (506) which
divides the elastic section into multiple resilient parts (508).
The multiple resilient parts are adapted to receive and support the
bearing and creates a compression force in radial direction
perpendicular to the axis of the shaft. This allows the bearing
retainer to hold the bearing in a fixed position with respect to
the bearing retainer. The elastic section comprises an oblique
subsection adjacent the ring section, which has a wall, which is
slanted with respect to the shaft of the pump. The bearing retainer
further comprises a cylindrical subsection adjacent the oblique
subsection, which has a wall, which is parallel to the shaft of the
pump.
FIG. 6 is a schematic perspective representation of a bearing
retainer (610) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer
has one ring section (602) adapted to surround the bearing, wherein
the ring section has an inner radius perpendicular to the axis of
the shaft. The bearing retainer has one elastic section (604)
adjacent the ring section, wherein at least a part of the elastic
section has an inner radius perpendicular to the axis of the shaft,
which inner radius is smaller than the radius of the ring section.
The elastic section comprises a part having a wave shaped form.
This wave shaped form provides a number of supporting points of
contact to a bearing (not shown). The elastic section comprises
multiple slits (606) which are parallel to the axis of the shaft
(not shown). The slits divide the elastic section into multiple
resilient parts (608). The multiple resilient parts are adapted to
receive and support the bearing and creates a compression force in
radial direction perpendicular to the axis of the shaft. This
allows the bearing retainer to hold the bearing in a fixed position
with respect to the bearing retainer. The elastic section comprises
an oblique subsection adjacent the ring section, which has a wall
which is slanted with respect to the shaft of the pump.
FIG. 7 is a schematic top view of a cross section through the
middle of a bearing retainer (710) according to an embodiment of
the invention. The bearing retainer holds a bearing (709) for
supporting the shaft of a pump. Visible features include multiple
slits (706) in the elastic section which divides the elastic
section into multiple resilient parts (708). The elastic section
comprises a part having a wave shaped form. This wave shaped form
provides a number of supporting points of contact to the bearing.
The multiple resilient parts are adapted to receive and support the
bearing and create a compression force in radial direction
perpendicular to the axis of the shaft. This allows the bearing
retainer to hold the bearing in a fixed position with respect to
the bearing retainer.
FIG. 8 is a schematic perspective representation of a bearing
retainer (810) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer
has one ring section (802) adapted to surround the bearing, wherein
the ring section has an inner radius perpendicular to the axis of
the shaft. The ring section (802) has a variable thickness in the
circumferential direction. The ring section (802) has an outer
profile that is wave formed and an inner radius that is constant.
The bearing retainer has one elastic section (804) adjacent the
ring section, wherein at least a part of the elastic section has an
inner radius perpendicular to the axis of the shaft, which inner
radius is smaller than the radius of the ring section. The elastic
section comprises multiple slits (806) which are linear with a bend
in each end. The slits (806) divides the elastic section into
multiple resilient parts (808). The multiple resilient parts are
adapted to receive and support the bearing and creates a
compression force in radial direction perpendicular to the axis of
the shaft. This allows the bearing retainer to hold the bearing in
a fixed position with respect to the bearing retainer.
FIG. 9 is a schematic perspective representation of a bearing
retainer (910) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer
has one ring section (902) adapted to surround the bearing, wherein
the ring section has an inner radius perpendicular to the axis of
the shaft. The bearing retainer has one elastic section (904)
adjacent the ring section, wherein at least a part of the elastic
section has an inner radius perpendicular to the axis of the shaft,
which inner radius is smaller than the radius of the ring section.
The elastic section comprises multiple slits (906) which are shaped
as a wave. The slits (906) divide the elastic section into multiple
resilient parts (908). The multiple resilient parts are adapted to
receive and support the bearing and creates a compression force in
radial direction perpendicular to the axis of the shaft. This
allows the bearing retainer to hold the bearing in a fixed position
with respect to the bearing retainer. The elastic section comprises
an oblique subsection adjacent the ring section, which has a wall,
which is slanted with respect to the shaft of the pump. The bearing
retainer further comprises a cylindrical subsection adjacent the
oblique subsection, which has a wall, which is parallel to the
shaft of the pump.
FIG. 10 is a schematic perspective representation of a bearing
retainer (1010) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer
has one ring section (1002) adapted to surround the bearing,
wherein the ring section has an inner radius perpendicular to the
axis of the shaft. The bearing retainer has one elastic section
(1004) adjacent the ring section, wherein at least a part of the
elastic section has an inner radius perpendicular to the axis of
the shaft, which inner radius is smaller than the radius of the
ring section. The elastic section comprises multiple slits (1006)
which are shaped like a wave. The slits (1006) divide the elastic
section into multiple resilient parts (1008). The multiple
resilient parts are adapted to receive and support the bearing and
creates a compression force in radial direction perpendicular to
the axis of the shaft. This allows the bearing retainer to hold the
bearing in a fixed position with respect to the bearing retainer.
The elastic section comprises an oblique subsection adjacent the
ring section, which has a wall, which is slanted with respect to
the shaft of the pump.
The bearing retainer further comprises a cylindrical subsection
adjacent the oblique subsection, which has a wall, which is
parallel to the shaft of the pump.
FIG. 11 is a schematic perspective representation of a bearing
retainer (10) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer is
placed in a holder (1101). The holder has an upper part (1103), a
lower part (1105) and a connecting belt (1107) which connect the
upper and lower part of the holder. The bearing retainer can act as
a spacer between the holder and the bearing.
FIG. 12 is a schematic perspective representation of a bearing
retainer (1210) according to an embodiment of the invention for a
bearing for supporting the shaft of a pump. The bearing retainer
has one ring section (1202) adapted to surround the bearing,
wherein the ring section has an inner radius perpendicular to the
axis of the shaft. The bearing retainer has one elastic section
(1204) adjacent the ring section, wherein at least a part of the
elastic section has an inner radius perpendicular to the axis of
the shaft, which inner radius is smaller than the radius of the
ring section. The elastic section comprises multiple slits (1206)
which divides the elastic section into multiple resilient parts
(1208). The multiple resilient parts are adapted to receive and
support the bearing and creates a compression force in radial
direction perpendicular to the axis of the shaft. This allows the
bearing retainer to hold the bearing in a fixed position with
respect to the bearing retainer. The bearing retainer has a first
end and a second end opposite the first end in an axial direction,
wherein the multiple slits (1206) extend to the ring sections of
the bearing retainer.
FIG. 13 shows a schematic sectional view through the guiding
chamber of a centrifugal pump according to an embodiment of the
invention showing an unassembled bearing (1309) and a bearing
retainer (1310), wherein the bearing (1309) may support the shaft
(not shown) of the pump. The bearing retainer is welded to the
inner guide cup of a guiding chamber of a centrifugal pump. FIG. 13
is rotated 180.degree. with respect to FIG. 1.
FIG. 14 is a schematic perspective representation of a bearing
retainer (1410) according to an embodiment of the invention,
wherein the bearing retainer holds a bearing (1409) for supporting
the shaft of a pump. The bearing retainer has one ring section
(1402) adapted to surround the bearing, wherein the ring section
has an inner radius perpendicular to the axis of the shaft. The
bearing retainer has one elastic section (1404) adjacent the ring
section, wherein at least a part of the elastic section has an
inner radius perpendicular to the axis of the shaft, which inner
radius is smaller than the radius of the ring section. The elastic
section comprises multiple slits (1406) which divides the elastic
section into multiple resilient parts (1408). The multiple
resilient parts are adapted to receive and support the bearing and
create a compression force in radial direction perpendicular to the
axis of the shaft. This allows the bearing retainer to hold the
bearing in a fixed position with respect to the bearing retainer.
The elastic section comprises an oblique subsection (1417) adjacent
the ring section, which has a wall, which is slanted with respect
to the shaft of the pump. The bearing retainer has a first end and
a second end opposite the first end in an axial direction, wherein
the multiple slits (1406) extend to the ring sections of the
bearing retainer.
FIG. 15 shows a schematic side view of a cross section of a bearing
retainer (1510) according to an embodiment of the invention. A
holder (1501) holds the bearing retainer (1510), which holds a
bearing (1509) supporting the shaft (1526) of a pump. The bearing
retainer has one ring section (1502) adapted to surround the
bearing (1509), wherein the ring section has an inner radius
(r.sub.1) perpendicular to the axis of the shaft. The bearing
retainer has two elastic sections (1504, 1504') adjacent the ring
section, wherein at least a part of the elastic section has an
inner radius (r.sub.2) perpendicular to the axis of the shaft,
which inner radius is smaller than the radius of the ring section.
The elastic section comprises multiple slits (not shown) which
divides the elastic section into multiple resilient parts. The
multiple resilient parts are adapted to receive and support the
bearing and creates a compression force in radial direction
perpendicular to the axis of the shaft. This allows the bearing
retainer to hold the bearing in a fixed position with respect to
the bearing retainer.
FIG. 16 shows a schematic side view of a cross section of a bearing
retainer (1610) according to an embodiment of the invention for a
bearing (1609) for supporting the shaft (1626) of a pump. There is
a second bearing (1613) which contacts and co-rotates with the
shaft (1626) of a pump. The bearing retainer has one ring section
(1602) adapted to surround the bearing, wherein the ring section
has an inner radius (r.sub.1) perpendicular to the axis of the
shaft. The bearing retainer has an elastic section (1604) adjacent
the ring section, wherein at least a part of the elastic section
has an inner radius (r.sub.2) perpendicular to the axis of the
shaft, which inner radius is smaller than the inner radius of the
ring section. The elastic section comprises multiple slits (not
shown) which divides the elastic section into multiple resilient
parts. The multiple resilient parts are adapted to receive and
support the bearing and creates a compression force in radial
direction perpendicular to the axis of the shaft. This allows the
bearing retainer to hold the bearing in a fixed position with
respect to the bearing retainer. The circles show a welding seam
(1615), which welds the bearing retainer (1602) to the stage guide
of the pump. The welding can be a continuous seam, or it can be
spot weldings. Other types of mechanical fixation are also
possible, though welding is the most common approach.
FIG. 17 shows a schematic cross section of a bearing retainer
(1710) according to an embodiment of the invention for a bearing
(1709) for supporting the shaft of a pump. The bearing retainer is
placed within a holder (1701). The holder has a sealed surface in
the bottom, which sealed surface comprises an opening, allowing the
shaft to pass through the sealed surface. The front part of the
retainer has been cut open to create a squared window, so that the
inner backside of the bearing retainer (1714) is visible. The arrow
indicates the direction of insertion of the bearing into the
bearing retainer. The bearing retainer (1710) has a ring section
(1702), and an elastic section adjacent the ring section (1702).
The elastic section comprises an oblique subsection (1717), and a
cylindrical subsection (1718) adjacent said oblique subsection
(1717), wherein said oblique subsection (1717) comprises a wall
which is slanted with respect to the shaft of the pump, and said
cylindrical subsection (1718) comprises a wall which is parallel to
the shaft of the pump. The slanted wall forms a curved slope,
connecting the ring section (1702) with the cylindrical subsection
(1718).
All cited references are incorporated by reference.
The accompanying Figures are provided to explain rather than limit
the present invention. It will be clear to the person skilled in
the art that aspects, embodiments and claims of the present
invention may be combined.
Unless otherwise mentioned, all measurements are conducted under
standard conditions (ambient temperature and pressure).
* * * * *